Speed Optimization WordPress (Manually)

functions.php

<?php

//defer css
function add_rel_preload($html, $handle, $href, $media) {
    
    if (is_admin())
        return $html;

     $html = <<<EOT
<link defer="defer" rel='stylesheet' href='$href' media="print" onload="this.media='all'" id='$handle' crossorigin="anonymous"/>
<noscript><link defer rel="preload" href="$href" crossorigin="anonymous"></noscript>
EOT;
    return $html;
}
add_filter( 'style_loader_tag', 'add_rel_preload', 10, 4 );


add_action('wp_head', 'hook_css');

//wphead cleanup
remove_action('wp_head', 'rsd_link'); // remove really simple discovery link
remove_action('wp_head', 'wp_generator'); // remove wordpress version

remove_action('wp_head', 'feed_links', 2); // remove rss feed links (make sure you add them in yourself if youre using feedblitz or an rss service)
remove_action('wp_head', 'feed_links_extra', 3); // removes all extra rss feed links

remove_action('wp_head', 'index_rel_link'); // remove link to index page
remove_action('wp_head', 'wlwmanifest_link'); // remove wlwmanifest.xml (needed to support windows live writer)

remove_action('wp_head', 'start_post_rel_link', 10, 0); // remove random post link
remove_action('wp_head', 'parent_post_rel_link', 10, 0); // remove parent post link
remove_action('wp_head', 'adjacent_posts_rel_link', 10, 0); // remove the next and previous post links
remove_action('wp_head', 'adjacent_posts_rel_link_wp_head', 10, 0 );
      
remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
remove_action( 'wp_print_styles', 'print_emoji_styles' );
      
remove_action('wp_head', 'wp_shortlink_wp_head', 10, 0); // Remove shortlink

/*
* Remove JSON API links in header html
*/
function remove_json_api () {

    // Remove the REST API lines from the HTML Header
    remove_action( 'wp_head', 'rest_output_link_wp_head', 10 );
    remove_action( 'wp_head', 'wp_oembed_add_discovery_links', 10 );

    // Remove the REST API endpoint.
    remove_action( 'rest_api_init', 'wp_oembed_register_route' );

    // Turn off oEmbed auto discovery.
    add_filter( 'embed_oembed_discover', '__return_false' );

    // Don't filter oEmbed results.
    remove_filter( 'oembed_dataparse', 'wp_filter_oembed_result', 10 );

    // Remove oEmbed discovery links.
    remove_action( 'wp_head', 'wp_oembed_add_discovery_links' );

    // Remove oEmbed-specific JavaScript from the front-end and back-end.
    remove_action( 'wp_head', 'wp_oembed_add_host_js' );

   // Remove all embeds rewrite rules.
   add_filter( 'rewrite_rules_array', 'disable_embeds_rewrites' );

}
add_action( 'after_setup_theme', 'remove_json_api' );

/*
	Snippet completely disable the REST API and shows {"code":"rest_disabled","message":"The REST API is disabled on this site."} 
	when visiting http://yoursite.com/wp-json/
*/
function disable_json_api () {

  // Filters for WP-API version 1.x
  add_filter('json_enabled', '__return_false');
  add_filter('json_jsonp_enabled', '__return_false');

  // Filters for WP-API version 2.x
  add_filter('rest_enabled', '__return_false');
  add_filter('rest_jsonp_enabled', '__return_false');

}
add_action( 'after_setup_theme', 'disable_json_api' );


function remove_cssjs_ver( $src ) {
    if( strpos( $src, '?ver=' ) )
        $src = remove_query_arg( 'ver', $src );
    return $src;
}
add_filter( 'style_loader_src', 'remove_cssjs_ver', 1000 );
add_filter( 'script_loader_src', 'remove_cssjs_ver', 1000 );

// Defer scripts
function mind_defer_scripts( $tag, $handle, $src ) {
  $defer = array(
    'custom-animate',
    'owl-carousel',
    'swiper-jquery',
    'jquery-migrate',
    'florida-custom',
    // 'custom_script',
    'scrolldepth',
    'tp-tools',
    'revmin',
    'jquery',
    // 'doubletab',
    'hoverIntent',
    'megamenu',
    'jquery-lazyloadxt',
    'jquery-lazyloadxt-srcset',
    'jquery-lazyloadxt-extend',
    // 'wpb_composer_front_js',
    // 'vc_accordion_script'
    'vc_carousel_js',
    'vc_tabs_script',
    'vc_tta_autoplay_script',
    'vc_transition_bootstrap_js',
    'mediaelement',
    'contact-form-7',
    'icegram_main_js',
    'dynamic-js',
    'wpcf7-redirect-script'
    // 'mediaelement-core'
  );
  if ( in_array( $handle, $defer ) ) {
     return '<script src="' . $src . '" defer="defer" type="text/javascript"></script>' . "\n";
  }
    
    return $tag;
} 
add_filter( 'script_loader_tag', 'mind_defer_scripts', 10, 3 );

// function PREFIX_remove_scripts() {
 
//     wp_dequeue_style( 'dashicons' );
//     // wp_dequeue_style( 'layerslider' );
//     wp_dequeue_style( 'ls-user' );
//     wp_dequeue_style( 'wp-block-library' );
//     wp_dequeue_style( 'ls-google-fonts' );
//     // wp_dequeue_style( 'layerslider-front' );
//     wp_dequeue_style( 'contact-form-7' );
//     wp_dequeue_style( 'rs-plugin-settings' );
//     wp_dequeue_style( 'gfont-style' );
//     wp_dequeue_style( 'flexslider' );
//     wp_dequeue_style( 'swiper-style' );
//     wp_dequeue_style( 'owl-theme-default' );
//     // wp_dequeue_style( 'js_composer_front' );
//     wp_dequeue_style( 'megamenu' );
//     wp_dequeue_style( 'admin-bar' );
//     wp_dequeue_style( 'yoast-seo-adminbar' );


//     wp_dequeue_script( 'dynamic-js' );
//     wp_dequeue_script( 'jquery' );
//     wp_dequeue_script( 'tp-tools' );
//     wp_dequeue_script( 'revmin' );

//     wp_dequeue_script( 'custom-animate' );
//     wp_dequeue_script( 'owl-carousel' );
//     wp_dequeue_script( 'swiper-jquery' );
//     wp_dequeue_script( 'jquery-migrate' );
//     // wp_dequeue_script( 'florida-custom' );
//     wp_dequeue_script( 'custom_script' );
//     wp_dequeue_script( 'scrolldepth' );
//     // wp_dequeue_script( 'doubletab' );
//     wp_dequeue_script( 'hoverIntent' );
//     wp_dequeue_script( 'megamenu' );
//     wp_dequeue_script( 'wpb_composer_front_js' );
//     wp_dequeue_script( 'vc_accordion_script' );
//     wp_dequeue_script( 'vc_carousel_js' );
//     wp_dequeue_script( 'vc_tabs_script' );
//     wp_dequeue_script( 'vc_tta_autoplay_script' );
//     wp_dequeue_script( 'vc_transition_bootstrap_js' );
//     wp_dequeue_script( 'contact-form-7' );
//     wp_dequeue_script( 'mediaelement-core' );
//     wp_dequeue_script( 'mediaelement' );
//     wp_dequeue_script( 'wpcf7-redirect-script' );
//     wp_dequeue_script( 'jquery-lazyloadxt' );
//     wp_dequeue_script( 'jquery-lazyloadxt-srcset' );
//     wp_dequeue_script( 'icegram_main_js' );

//     wp_dequeue_script( 'jquery-lazyloadxt-extend' );

//     wp_dequeue_script( 'another-jquery' );

//     // Now register your styles and scripts here
// }
// add_action( 'wp_enqueue_scripts', 'PREFIX_remove_scripts', 20 );

// function prefix_add_footer() {

//     wp_enqueue_style( 'dashicons');
//     // wp_enqueue_style( 'layerslider');
//     wp_enqueue_style( 'ls-user');
//     wp_enqueue_style( 'wp-block-library');
//     wp_enqueue_style( 'ls-google-fonts');
//     // wp_enqueue_style( 'layerslider-front');
//     wp_enqueue_style( 'contact-form-7');
//     wp_enqueue_style( 'rs-plugin-settings');
//     wp_enqueue_style( 'gfont-style');
//     wp_enqueue_style( 'flexslider');
//     wp_enqueue_style( 'swiper-style');
//     wp_enqueue_style( 'owl-theme-default');
//     // wp_enqueue_style( 'js_composer_front');
//     wp_enqueue_style( 'megamenu');
//     wp_enqueue_style( 'admin-bar');
//     wp_enqueue_style( 'yoast-seo-adminbar');


//     wp_enqueue_script( 'dynamic-js');
//     wp_enqueue_script( 'jquery' );
//     // wp_enqueue_script( 'doubletab' );
//     wp_enqueue_script( 'tp-tools' );
//     wp_enqueue_script( 'revmin' );

//     wp_enqueue_script( 'custom-animate' );
//     wp_enqueue_script( 'owl-carousel' );
//     wp_enqueue_script( 'swiper-jquery' );
//     wp_enqueue_script( 'jquery-migrate' );
//     // wp_enqueue_script( 'florida-custom' );
//     wp_enqueue_script( 'custom_script' );
//     wp_enqueue_script( 'scrolldepth' );
    
    
//     wp_enqueue_script( 'hoverIntent' );
//     wp_enqueue_script( 'megamenu' );
//     wp_enqueue_script( 'wpb_composer_front_js' );
//     wp_enqueue_script( 'vc_accordion_script' );
//     wp_enqueue_script( 'vc_carousel_js' );
//     wp_enqueue_script( 'vc_tabs_script' );
//     wp_enqueue_script( 'vc_tta_autoplay_script' );
//     wp_enqueue_script( 'vc_transition_bootstrap_js' );
//     wp_enqueue_script( 'contact-form-7' );
//     wp_enqueue_script( 'mediaelement-core' );
//     wp_enqueue_script( 'mediaelement' );
//     wp_enqueue_script( 'wpcf7-redirect-script' );
//     wp_enqueue_script( 'jquery-lazyloadxt' );
//     wp_enqueue_script( 'jquery-lazyloadxt-srcset' );
//     wp_enqueue_script( 'icegram_main_js' );
//     // wp_enqueue_script( 'jquery-lazyloadxt-extend' );
//     // wp_enqueue_script( 'another-jquery' );
// };
// add_action( 'get_footer', 'prefix_add_footer' );

// html compressor
class WP_HTML_Compression
{
    // Settings
    protected $compress_css = true;
    protected $compress_js = false;
    protected $info_comment = true;
    protected $remove_comments = true;

    // Variables
    protected $html;
    public function __construct($html)
    {
   	 if (!empty($html))
   	 {
   		 $this->parseHTML($html);
   	 }
    }
    public function __toString()
    {
   	 return $this->html;
    }
    protected function bottomComment($raw, $compressed)
    {
   	 $raw = strlen($raw);
   	 $compressed = strlen($compressed);
   	 
   	 $savings = ($raw-$compressed) / $raw * 100;
   	 
   	 $savings = round($savings, 2);
   	 
   	 return '<!--HTML compressed, size saved '.$savings.'%. From '.$raw.' bytes, now '.$compressed.' bytes-->';
    }
    protected function minifyHTML($html)
    {
   	 $pattern = '/<(?<script>script).*?<\/script\s*>|<(?<style>style).*?<\/style\s*>|<!(?<comment>--).*?-->|<(?<tag>[\/\w.:-]*)(?:".*?"|\'.*?\'|[^\'">]+)*>|(?<text>((<[^!\/\w.:-])?[^<]*)+)|/si';
   	 preg_match_all($pattern, $html, $matches, PREG_SET_ORDER);
   	 $overriding = false;
   	 $raw_tag = false;
   	 // Variable reused for output
   	 $html = '';
   	 foreach ($matches as $token)
   	 {
   		 $tag = (isset($token['tag'])) ? strtolower($token['tag']) : null;
   		 
   		 $content = $token[0];
   		 
   		 if (is_null($tag))
   		 {
   			 if ( !empty($token['script']) )
   			 {
   				 $strip = $this->compress_js;
   			 }
   			 else if ( !empty($token['style']) )
   			 {
   				 $strip = $this->compress_css;
   			 }
   			 else if ($content == '<!--wp-html-compression no compression-->')
   			 {
   				 $overriding = !$overriding;
   				 
   				 // Don't print the comment
   				 continue;
   			 }
   			 else if ($this->remove_comments)
   			 {
   				 if (!$overriding && $raw_tag != 'textarea')
   				 {
   					 // Remove any HTML comments, except MSIE conditional comments
   					 $content = preg_replace('/<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->).)*-->/s', '', $content);
   				 }
   			 }
   		 }
   		 else
   		 {
   			 if ($tag == 'pre' || $tag == 'textarea')
   			 {
   				 $raw_tag = $tag;
   			 }
   			 else if ($tag == '/pre' || $tag == '/textarea')
   			 {
   				 $raw_tag = false;
   			 }
   			 else
   			 {
   				 if ($raw_tag || $overriding)
   				 {
   					 $strip = false;
   				 }
   				 else
   				 {
   					 $strip = true;
   					 
   					 // Remove any empty attributes, except:
   					 // action, alt, content, src
   					 $content = preg_replace('/(\s+)(\w++(?<!\baction|\balt|\bcontent|\bsrc)="")/', '$1', $content);
   					 
   					 // Remove any space before the end of self-closing XHTML tags
   					 // JavaScript excluded
   					 $content = str_replace(' />', '/>', $content);
   				 }
   			 }
   		 }
   		 
   		 if ($strip)
   		 {
   			 $content = $this->removeWhiteSpace($content);
   		 }
   		 
   		 $html .= $content;
   	 }
   	 
   	 return $html;
    }
   	 
    public function parseHTML($html)
    {
   	 $this->html = $this->minifyHTML($html);
   	 
   	 if ($this->info_comment)
   	 {
   		 $this->html .= "\n" . $this->bottomComment($html, $this->html);
   	 }
    }
    
    protected function removeWhiteSpace($str)
    {
   	 $str = str_replace("\t", ' ', $str);
   	 $str = str_replace("\n",  '', $str);
   	 $str = str_replace("\r",  '', $str);
   	 
   	 while (stristr($str, '  '))
   	 {
   		 $str = str_replace('  ', ' ', $str);
   	 }
   	 
   	 return $str;
    }
}

function wp_html_compression_finish($html)
{
    return new WP_HTML_Compression($html);
}

function wp_html_compression_start()
{
    ob_start('wp_html_compression_finish');
}
add_action('get_header', 'wp_html_compression_start');

// remove_action('wp_head', 'wp_print_scripts');
// remove_action('wp_head', 'wp_print_head_scripts', 9);
// remove_action('wp_head', 'wp_enqueue_scripts', 1);
// add_action('wp_footer', 'wp_print_scripts', 5);
// add_action('wp_footer', 'wp_enqueue_scripts', 5);
// add_action('wp_footer', 'wp_print_head_scripts', 5);